It will be appreciated that engines are relatively complicated assemblies incorporating a number of moving components with appropriate seals between them. These seals may fail or through other factors there may be leakage of a fluid, such as oil, hydraulic fluid, coolant or otherwise. Clearly, such leakage is indicative of some form of failure within the engine in terms of sealing or otherwise. In such circumstances, it is necessary to provide some form of signal flag indicating that failure.
Traditionally, a drainage tube has been utilized through which the leakage passes. The tube is dimensioned whereby a droplet of the relevant liquid remains at the end of the drainage tube when engine operation ceases. In such circumstances during a regular maintenance check, presence of such a droplet at the end of the drain indicates an underlying leakage problem within the engine to be corrected.
Inherent problems with such visual and manual detection of leakage is with respect to the potential for missing the presence of a leakage droplet at the end of the drain, the time span between maintenance/service checks and the difficulty with regard to distinguishing different fluids. It will be understood that the fluid leakages from the engine are captured and led down the drain and that normally there are several drain passages at the bottom of the engine housing. These drains are of a tubular nature with a diameter such that a drop of leaking fluid is normally retained at the end of the tube. However, this droplet may not be retained as a so-called “wet tube” with the result that particularly under poor maintenance conditions, small leaks may go undetected for considerable periods of time resulting in a more serious problem developing.
Turbulence is created where the drains protrude from the engine casing, so it is beneficial to minimize the number of such protuberances.